[tor-bugs] #17694 [Tor]: Hash PRNG output before use, so that it's not revealed to the network

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#17694: Hash PRNG output before use, so that it's not revealed to the network
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     Reporter:  teor         |      Owner:
         Type:  enhancement  |     Status:  new
     Priority:  Medium       |  Milestone:  Tor: 0.2.8.x-final
    Component:  Tor          |    Version:  Tor: unspecified
     Severity:  Normal       |   Keywords:
Actual Points:               |  Parent ID:
       Points:               |    Sponsor:
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 In a review of prop250, ioerror suggests that we should hash raw random
 values before revealing them to the network.

 https://lists.torproject.org/pipermail/tor-dev/2015-November/009954.html

 This avoids an attack similar to the one that broke Dual EC:
 http://projectbullrun.org/dual-ec/ext-rand.html

 I have a patch for this, I need to clean it up to merge cleanly on top of
 #17686.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/17694>
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